Energy generation and storage system with electric vehicle charging capability

ABSTRACT

An inverter includes a battery pack connection for supplying energy to or receiving energy from a photovoltaic string, a battery pack, an AC grid connection for supplying power to or receiving power from an AC grid, a connection for supplying power to a home back-up load, an electric vehicle connection for supplying to and receiving power from an electric vehicle (EV) battery, and a control input configured to receive one or more control signals for controlling the flow of power within the inverter. The inverter, under the control of the one or more control signals, converts power received from one of different power sources and provides the converted power to charge a battery of the EV.

CROSS-REFERENCES TO RELATED APPLICATIONS

This claims the benefit of priority under 35 U.S.C. § 119(e) to U.S.Provisional Application No. 62/370,582, filed Aug. 3, 2016, which ishereby incorporated by reference in its entirety and for all purposes.

BACKGROUND

The disclosure relates generally to energy generation systems, and moreparticularly, to integrated solar energy generation, energy storage andelectric vehicle charging systems.

In the United States only about one percent of homes currently areequipped with solar panels, and only about 1 percent of these homes arestoring the generated electric power in batteries. A basic solar systemconsists of an array of panels oriented to receive direct sunlight, oneor more inverters to convert the DC power from the array of solar panelsto AC, and a physical interface to the customer's existing electricalsystem. Inverters come in two main form factors—micro-inverters, whichare small inverters connected directly to one or more panels at thepoint of the array, and string inverters which receive the aggregatedserialized output of several solar panels. An average solar powered U.S.home may have a 5 to 6 kW array requiring a 5 to 6 kW PV stringinverter. This size system typically generates about 1,200 to 1,800 kWhof electricity per month depending on the geographical location and timeof the year. Since a 3-bedroom home typically utilizes about 800 to1,000 kWh per month, customers often generate excess energy, inparticular during the summer. That excess electric energy can be fed tothe utility grid. The process of back feeding excess power to the gridis known as net energy metering (NEM) or simply net metering. Existingnet energy metering (NEM) incentives for PV inverters are about 8 to 12cents/kWh. In other words, customers are compensated or credited by theutility in that amount for each kWh of power supplied to the grid. Thisexcess energy can be used to offset the customers' consumption duringtimes of year when solar power product is lower (e.g., during winter).Although popular with solar customers, net metering is increasinglyunder attack from entrenched utilities who want to compensate customersat lower rates, add monthly self-generation charges, and in some casespenalize customers for back feeding any power to the grid. This changein the regulatory landscape has made widespread deployment of storagecritical to the continued growth of solar. By storing power generatedduring the day, customers can then utilize that power at night, reducingtheir reliance on grid power while maximizing the value of their solarsystem without needing NEM.

Electric vehicles (EVs) have also gained popularity recently due togreat advances in lithium-ion battery technology that extends the rangeof EVs above 200 miles, drastic reduction in costs year over year,exciting new models of electric cars that rival or surpass theperformance of comparable gasoline powered cars, and increased interestin supporting clean energy. These factors have caused the automotiveindustry to begin to shift focus to develop more electric vehicles(EVs). Products such as the Chevy Volt, Nissan Leaf, and Tesla Model Sare currently very popular in the market. The energy capacity of thebatteries used in these exemplary EVs varies widely. For example, thecapacity of Chevy Volt's battery is 25 kWh, that of Nissan leaf is 35kWh, and that of Tesla Model S ranges from 60 to 100 kWh. On average,every kWh of energy can provide about 3 to 5 miles of driving range tothese EVs.

EV drivers have to charge their vehicles regularly, either at home, atwork, or in one of many publically available EV charging stations (e.g.,shopping centers, privately owned charging stations, or in the case ofTesla, one of the proprietary stations in their network ofSuperchargers). The number of miles of range obtained per unit ofcharging time will depend on how much current is conducted by thecharger. Today's chargers for EVs can be categorized into three types:slow chargers that supply about 5 kW, medium chargers that supply about15 to 30 kW, and fast chargers that supply about 100 to 135 kW.

The proliferation of EVs will increased the demand for electricity andshould have a positive effect on the adoption of solar. However, thegeneration of solar energy has a diurnal cycle, and is therefore not beavailable in the nighttime when EVs often need to be charged. Therefore,storage of electrical energy for continuous electricity provision at anytime of the day and advanced electric charging systems also need to bedeveloped along with the increased deployment of EVs. Current solarenergy generation and storage systems provide no provisions for directcharging of EVs. Rather EVs are charged by the power provided directlyfrom the utility grid, usually via a special charger customers canpurchase from the automaker or a third party that plugs into aconventional 120V or 240V wall outlet. Thus, there is a need for anintegrated solar energy generation and storage system with efficient andcost effective EV charging capability.

BRIEF SUMMARY OF THE INVENTION

This disclosure describes various embodiments that relate to systems andapparatuses for cost effectively providing power to one or more homeback-up loads, charging batteries of one or more electric vehicles, andchanneling any excess power to the AC grid or to battery packs forbackup and/or delayed consumption. The systems and apparatuses of thedisclosure may include a renewable energy source (e.g. solar panels)coupled to an inverter. The inverter may include a bidirectional batterypack connection configured to supply energy to or receive energy fromthe battery packs, a bidirectional AC grid connection configured tosupply or receive power from the AC grid, an output connectionconfigured to supply power to a back-up load, and an electric vehicleconnection configured to supply power to or receive power from anelectric vehicle (EV). The systems and apparatuses of the disclosure mayfurther include a control input terminal configured to receiveinstructions from a user or from a controller device to control thepower flow within the inverter.

In accordance with the present disclosure, any excess energy generatedby a renewable energy source can be stored in local battery packs or inan EV. In some embodiments, the battery packs can directly supply DCpower to an EV. In other embodiments, energy stored in the EV can beused to supply to one or more back-up loads in the event of poweroutage. Embodiments of the present disclosure thus provide a flexibleand efficient use of renewable energy and exploit the advance in EVbattery technology.

In some embodiments, an inverter supplies any excess energy to one ormore battery packs. In normal operating conditions, the inverter maychannel the excess energy to the AC grid. In high power demandsituations, the inverter may combine power from the AC grid, from thebattery pack, and/or from a renewable energy source (e.g., solar panelson sunny days). In bad weather or needed conditions, the inverter mayprovide power to one or more back-up loads or to the EV from the batterypacks. In a power outage event, the inverter may provide power to theback-up load from the battery packs or from the EV (e.g., when thebattery packs are depleted). In other words, the EV battery can be usedas a mobile emergency power source to backup home loads through theinverter.

In some embodiments, an inverter may include a battery pack connectionfor supplying energy to or receiving energy from a battery pack, an ACgrid connection for supplying power to or receiving power from an ACgrid, a connection for supplying power to a back-up load, an electricvehicle connection for supplying power to and receiving power from anelectric vehicle (EV), and a control input configured to receive one ormore control signals for controlling the flow of power within theinverter. The inverter, autonomously or under the control of the one ormore control signals, inverts power received from the battery pack andprovides the inverted power to charge a battery of the EV.

In one embodiment, the inverter is a storage inverter that furtherincludes a DC/DC buck-boost stage configured to couple to the batterypack, and a DC/AC inverter configured to selectively couple to agrid-tied PV inverter, to the AC grid and to the home back-up load.

In one embodiment, the storage inverter includes a DC car port coupledto the DC/DC buck-boost stage and configured to supply DC power to orreceive DC power from the battery of the EV.

In one embodiment, the inverter is a hybrid inverter that furtherincludes a first DC/DC buck-boost stage configured to couple to one ormore PV strings, and a DC/AC inverter configured to selectively coupleto the AC grid, to the back-up load, and to the battery of the EVautonomously or under the control of the one or more control signals.The hybrid inverter may further include a second DC/DC buck-boost stagecoupled between the first DC/DC buck-boost stage and the battery packand configured to supply power to the battery pack or receive power fromthe battery pack.

In one embodiment, the hybrid inverter may further include a DC car portconnection coupled to the second DC/DC buck-boost stage and configuredto supply DC power to or receive DC power from the battery of the EV.

Some embodiments of the present invention also provide a system forenergy conversion with electric vehicle charging capability. The systemincludes a photovoltaic (PV) inverter configured to receive DC powerprovided by a photovoltaic (PV) string and generate AC power, and astorage inverter coupled to the PV inverter. The storage inverterincludes a battery pack connection for supplying energy to or receivingenergy from a battery pack, an AC grid connection for supplying power toor receiving power from an AC grid, a connection for supplying power toa home back-up load, an electric vehicle connection for supplying powerto or receiving power from an electric vehicle (EV) battery, and acontroller for generating one or more control signals to control theflow of power through both the PV inverter and the storage inverter. Thesystem, autonomously or under the control of the one or more controlsignals, converts power received from one of the PV string and thebattery pack and provides the converted power to charge the EV battery.

Embodiments of the present invention also provide a system for energyconversion with electric vehicle charging capability. The systemincludes a hybrid inverter which contains a first DC/DC converter stageconfigured to receive power from a photovoltaic (PV) array, a capacitorbank coupled to the first DC/DC converter stage and configured to storeDC energy, a DC-AC inverter coupled to the capacitor bank, a batterypack connection for supplying energy to or receiving energy from abattery pack, an AC grid connection for supplying power to or receivingpower from an AC grid, a connection for supplying power to a homeback-up load, and an electric vehicle connection for supplying power toor receiving power from an electric vehicle (EV) battery. The systemalso includes a controller for generating one or more control signals tocontrol the flow of power within the hybrid inverter. The hybridinverter, under the control of the one or more control signals, convertspower received from the PV array and the battery pack and provides theconverted power to charge the EV battery.

Other aspects and advantages of the invention will become apparent fromthe following detailed description taken in conjunction withaccompanying drawings which illustrate, by way of example, theprinciples of the described embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to facilitate a better understanding of the present disclosure,reference is now made to the accompanying drawings, in which likeelements are referenced with like numerals. These drawings should not beconstrued as limiting the present disclosure, but are intended to beexemplary only.

FIG. 1 is a block diagram of an exemplary AC coupled solar energygeneration and storage system with electric vehicle charging capability,according to embodiments of the present disclosure;

FIG. 1A is a connection diagram of an interconnection device providingmultiple operation modes to a solar energy generation and storage systemwith electric vehicle charging capability, according to some embodimentsof the present disclosure;

FIG. 2 is a block diagram of an exemplary AC coupled solar energygeneration and storage system with multiple battery packs and electricvehicle charging capability, according to other embodiments of thepresent disclosure;

FIG. 3 is a block diagram of an exemplary AC coupled solar energygeneration and storage system with AC battery and electric vehiclecharging capability, according to other embodiments of the presentdisclosure;

FIG. 4 is a block diagram of an exemplary DC coupled solar energygeneration and storage system with electric vehicle charging capability,according to still other embodiments of the present disclosure;

FIG. 5 is a block diagram of an exemplary DC coupled solar energygeneration and storage system with multiple battery packs and electricvehicle charging capability, according to still other embodiments of thepresent disclosure;

FIG. 6 is a block diagram of an exemplary AC coupled solar energygeneration and storage system with electric vehicle charging capabilityincluding a PV inverter and multiple storage inverters and associatedbattery packs, according to still other embodiments of the presentdisclosure;

FIG. 7 is a block diagram of an exemplary DC coupled solar energygeneration and storage system with electric vehicle charging capabilityincluding multiple hybrid inverters and associated battery packs,according to still other embodiments of the present disclosure;

FIG. 8 is a block diagram of an exemplary solar energy generation andstorage system with electric vehicle charging capability including an ACcoupled solar energy generation and storage system and one or morehybrid inverters and associated battery packs, according to still otherembodiments of the present disclosure;

FIG. 9 illustrates a block diagram of an exemplary solar energygeneration and storage system with electric vehicle charging capabilityincluding a PV inverter and one or more hybrid inverters and associatedbattery packs, according to still other embodiments of the presentdisclosure;

FIG. 10 is a block diagram of an exemplary solar energy generation andstorage system with electric vehicle charging capability including asingle stage PV inverter and a storage inverter, according to stillother embodiments of the present disclosure;

FIG. 11 is a block diagram of an exemplary solar energy generation andstorage system with electric vehicle charging capability including asingle stage PV inverter with a PV optimizer and a storage inverter,according to still other embodiments of the present disclosure; and

FIG. 12 is a block diagram of an exemplary solar energy generation andstorage system with electric vehicle charging capability includingmicro-inverters and a storage inverter, according to still otherembodiments of the present disclosure.

DETAILED DESCRIPTION

According to embodiments described in this disclosure, an inverter foruse in a renewable energy generation and storage system includes abidirectional battery pack input for supplying energy to or receivingenergy from a battery pack, a bidirectional grid connection forsupplying power to or receiving power from the AC grid, an outputconnection for supplying power to a back-up load(s), an electric vehicle(EV) connection for supplying power to and receiving power from an EV,and a control input for receiving one or more control signals to controlthe direction of power flow within the inverter. In some variations, theelectric vehicle connection is a bidirectional connection so that the EVmay also supply power through the inverter. In other variations, theinverter is a storage inverter that further includes a DC/DC buck-booststage configured to couple to a battery pack, and a DC/AC inverter stageconfigured to selectively couple to a PV inverter, to the AC grid and tothe back-up load(s). In other variations, the EV connection may be an ACconnection coupled to the DC/AC inverter stage, or a DC connectionconfigured to couple to the battery pack. These and other variationsdescribed in this disclosure advantageously enable the solar energygeneration and storage system to provide power to charge one or moreEVs. The inverter may be configured to enable the EV battery to becharged by one or more of PV modules, battery pack and AC grid. Theinverter may also be configured to allow the EV battery to supply powerthrough the inverter to, for example, the home back-up load(s) when PVpower and/or the AC grid are not available, or to the AC grid duringpeak demand hours. It is noted that while the various inverter andsystem embodiments described in this disclosure are in the context ofsolar energy systems, one skilled in this art would know how to modifythe various inverter and system embodiments for use in other renewablesystems such as fuel cell systems or wind energy generation systems inview of this disclosure.

FIG. 1 illustrates a block diagram of an exemplary solar energygeneration and storage system 100 with electric vehicle chargingcapability. System 100 includes photovoltaic (PV) string(s) (or PVarray) 104 connected to grid-tied PV inverter 106. The grid-tied PVinverter 106 includes DC side 108 and AC side 110 that are connected toone another via central capacitor bank 112. DC side 108 may includecircuitry for performing maximum power point tracking (MPPT) on PVarray, and DC/DC boost stage 109 for boosting or bypassing the stringvoltage provided by PV string(s) 104. AC side 110 converts the energyfrom capacitor bank 112 to AC current via DC/AC inverter 111 to supplyto home backup loads 116 and AC grid 114. This typically involvessynchronizing the voltage and phase of the PV inverter current/power tothe AC grid interconnection or storage inverter voltage. The AC grid isnot limited to single-phase but is also applicable to three-phasesystem, e.g., 120 Vac, 208 Vac, 230 Vac, 240 Vac, 277 Vac, 400 Vac, 480Vac, 690 Vac, and the like. DC/AC inverter 111 may have an outputconfigured to provide power to AC grid 114, or to power one of the homeback-up loads 116 (e.g., refrigerator, washing machine, air conditioner,microwave oven, etc.) through storage inverter 118, and/or chargebattery pack 102 through storage inverter 118 in an off-grid situation.

System 100 also has storage inverter 118 connected to a battery pack 102including one or more battery modules (groups of cells) 124. Thisarrangement of the battery pack is called an AC-coupled system becausethe interface between storage inverter 118 and PV inverter 106 is an ACinterface 151. System 100 is advantageous where, for example, the PVinverter already exists, and the user wants to add storage and EVcharging capacity at later times as retrofit.

During battery pack charging, storage inverter 118 functions as arectifier or performs switching converting the AC power into DC powerfor charging battery modules 124. The power for charging battery modules124 may come from PV string(s) 104, from AC grid 114, or from both powersources combined or EV battery 144. Storage inverter 118 functions thesame regardless of which power source(s) charge battery modules 124.Power may flow through DC/DC buck-boost stage 120, which steps thevoltage down to the appropriate level for charging battery modules 124.The purpose of DC/DC buck-boost stage 120 is two-fold. One, to theextent necessary, it will buck the rectified DC voltage down to thelevel of battery modules 124. For example, if the rectified DC voltageexceeds battery modules' maximum allowable voltage, which it typicallywill since both AC grid 114 and PV inverter 106 provide at least 170volts, it will buck that voltage down to a safe level of battery modules124.

Second, during discharge of battery modules 124, power leaving batterymodules 124 may again flow through DC/DC buck-boost stage 120 where itis stepped up to over or match grid voltage levels (e.g., 170 volts)before inversion to AC (by DC-AC inverter 122) for supply to AC grid 114or back-up loads 116. A DC link (capacitor bank) 119 is disposed betweenDC/DC buck-boost stage 120 and DC-AC inverter 122. DC-AC (DC/AC)inverter 122 is a bidirectional inverter that can receive power from theAC grid and provide DC power to the battery pack.

In some embodiments, the function of DC/DC buck-boost stage 120 may beperformed by DC/DC buck/boost stage 126 housed in battery pack 102. Thatis, either the DC/DC buck-boost stage is located in storage inverter 118or in battery pack 102, or both sometimes. The asterisk “*” denotes thepossible locations for the buck-boost stage: either at the storageinverter, at the battery pack, or at both. The amount of boost or buckthat occurs will depend on the voltage level of battery pack 102.Battery pack 102 may also include a battery management system (BMS) 125for management and control of battery modules 124. This concept is alsoapplicable in non-PV systems that only have a storage inverter betweenthe battery modules, the AC grid, and back-up load(s).

System 100 also includes electric vehicle charging capability. Electricvehicle (EV) 140 includes bidirectional AC/DC converter 142 that can beconnected to AC car port 123 of storage inverter 118 via a chargingcable and car plug. AC/DC converter 142 can receive AC power fromstorage inverter 118 that receives power from PV string(s) 104, frombattery pack 102, or from both through car port 123. Alternatively, EV140 can supply AC power via bidirectional AC/DC converter 142 and AC carport 123 to power back-up loads 116 (indicated by connection 152) oreven to AC grid (indicated by connection 155). Car port 123 may also beconnected to the AC grid through storage inverter 118 (indicated byconnections 152, 153, 155), directly to the AC grid (indicated byconnection 154), or with an external bypass mechanism.

System 100 may also include a DC car port 156 that enables a low-voltageDC charging of EV 140 when the EV battery 144 is a low-voltage battery(e.g. 48 V) and can be charged directly from the battery pack 102. DCcar port 156 is a terminal connected between battery pack 102 andbuck-boost stage 120. System 100 may also include a DC car port 156′that enables a high-voltage charging of EV 140 when the EV battery 144is a high-voltage battery (e.g., 400V, 1000V). In this high-voltage EVcharge scenario, the AC/DC conversion may be bypassed. DC car port 156′is a terminal connected at DC link 119 between buck-boost stage 120 andDC-AC inverter 122. The DC low-voltage connection for charging isdenoted by reference numeral 157 and the DC high-voltage connection forcharging the EV is denoted by reference numeral 157′. System 100 mayalso include a DC car port 156″ that enables a high-voltage DC chargingof EV 140 when PV string(s) 104 generates sufficient electric energy. DCcar port 156″ is a terminal connected to central capacitor bank 112 andconfigured to supply DC power to EV 140 through a bidirectional DCconnection 157″. For example, when PV string(s) 104 generates sufficientelectrical power, the (high-voltage) battery 144 of EV 140 may bedirectly DC charged from DC/DC boost stage 109. When the PV string(s) isunable to provide adequate power, EV 140 may supply DC power to the PVinverter 106 through the DC car port connection 157″ to power the homeback-up load(s).

System 100 also includes site controller 130 configured to control thepower flow within the system. For example, during on-grid, sitecontroller 130 may cause storage inverter 118 to charge battery modules124 from AC grid 114 (through connection 155) or from PV string(s) 104(through connection 151). During off-grid, site controller 130 may causestorage inverter 118 to charge battery modules 124 from PV string(s) 104(through connection 151) or supply power to AC grid (through connections153, 155). Site controller may include multiple individual anddistributed microcontrollers located in the PV inverter, in the batterypack, and in the storage inverter, the individual microcontrollers maycommunicate with each other through a controller bus (e.g., a controllerarea network bus or modbus or similar communication means) to handle thepower flow within the system. Storage inverter 118 controls the powerflow to the back-up loads via internal anti-islanding and transferrelays during on-grid and off-grid situations. Storage inverter 118 mayhave AC car port 123 for charging EV 140 from battery pack 102 or fromPV string(s) 104, or from both sources. It is noted that theanti-islanding relays (not shown) are present after the DC/AC stage inboth inverters and before the transfer relays (not shown) in the storageinverter. Anti-islanding relays together with the transfer relays routepower under the control of controller 130. For slow charging, the totalcharging power could be limited to the individual power ratings or thecombination of both for fast charging. For example, the PV inverter mayhave a power rating equal to or less than 5 to 6 kW, and the storageinverter may have a power rating equal to or less than 6 kW, so thattogether they can supply power equal to or less than 6 kW or less than12 kW when combined. Site controller 130 may be configured by a user toset the charging priority, i.e., whether to supply power from the PVinverter only, from the storage inverter only, or from both, and inwhich order. In instances where the power from PV inverter 106 andstorage inverter 118 is not sufficient, or more power is required,additional power may be drawn from AC grid 114 to charge EV 140.

FIG. 1A is a connection diagram of an interconnection device (apparatus)10 configured to support multiple operation modes of a solar energygeneration and storage system according to some embodiments of thepresent disclosure. Connection device 10 includes a plurality ofconnections, each of which may include one or more switches (e.g.,solid-state relays, electronic switches, electro-mechanical relays). Insome embodiments, connection device 10 may have a multitude of switchesdisposed between the inverter (e.g., PV inverter, storage inverter) andbackup load(s), between the backup load(s) and the AC grid, between theAC car port and the AC grid or the backup load(s), etc. Connectiondevice 10 is configured to selectively connect backup load(s), the ACgrid, the inverter, and the AC car port with each other under thecontrol of a controller (e.g., the site controller 130).

Referring to FIG. 1A, connection device 10 may include a first terminal12 for connecting to a DC/AC inverter 11. DC/AC inverter 11 may be theDC/AC inverter 122 or storage inverter 118 of FIG. 1. Connection device10 further includes a second terminal 12′ configured to establishelectrical connection to another inverter, such as DC/AC inverter 111 ofPV inverter 106 (FIG. 1). Connection device 10 also includes a thirdterminal 13 configured to establish a connection to an external EV, afourth terminal 14 configured to establish a connection to the AC grid,and a fifth terminal 15 configured to establish a connection to homebackup loads. The first, second, third, fourth and fifth terminals areselectively connected to each other through a plurality of switches,e.g., S1, S2, S3, S4, S5, which are controlled by control signalsprovided by a controller. Single-pole single-throw (SPST), single-poledouble-throw (SPDT), double-pole double-throw (DPDT) or any suitableconfiguration can be used for switches S1, S2, S3, S4, S5. In someembodiments, the connection device can be located inside the storageinverter.

First terminal 12 and third terminal 13 are electrically andmechanically connected to each other through switches S1, S3 and S5.First terminal 12 (and second terminal 12′) and fourth terminal 14 areelectrically and mechanically connected to each other through switchesS1 and S3. First terminal 12 and fifth terminal 15 are electrically andmechanically connected to each other through switches S3 and S4.Connection device 10 may further include an input port configured toreceive control signals generated by a controller (e.g., site controller130). The controller may issue control signals to selectively open orclose the switches based on the performance of the solar energygeneration and storage system (e.g., system 100 of FIG. 1). For example,the controller monitors the AC grid. If the voltage of the AC grid dropsbelow a predetermined value, the controller may activate switches S3 andS4 in the manner that power to the backup load(s) is supplied by theDC/AC inverter instead by the AC grid. The controller may also activateswitches S1, S2, S3, S4 to supply power to the backup loads(s) and tothe AC grid when it determines that the battery modules in the batterypack are fully charged and there is excess energy available from the PVstrings. The controller may further activate (close) switch S5 if itdetermines that an EV battery is connected to terminal 13 to charge theEV battery.

In some embodiments, the controller may detect an islanding conditionand activate (open) switch S1 to electrically disconnect the output ofthe DC/AC inverter from the AC grid. In some embodiments, switch S1 maybe an anti-islanding relay that includes logic to detect the islandingcondition and automatically disconnect the DC/AC inverter from the ACgrid and connect the DC/AC inverter to a synchronization mechanism(e.g., a phase-locked loop) to maintain the phase and frequency of theDC/AC inverter output.

In some embodiments, switches S2 and S3 may be a transfer relay that mayinclude logic that directs the power flow from one power supply toanother. For example, switches S2 and S3 may be open so that power of PVstring(s) 104 can flow through the DC/AC inverter to charge batterymodules 124 when the battery pack is not fully charged or depleted. Forexample, switch S3 may establish an electrical connection between theDC/AC inverter and the AC grid to supply power to the AC grid to getsome credit when system 100 has surplus energy (a sunny day and thebattery pack is fully charged). For example, a connection can beestablished through switches S3 and S4 so that the DC/AC converter cansupply power to the backup load(s) when the AC grid is not available.

In some embodiments, switch S5 may have logic that activates (opens) theconnection to terminal 13 in the event that a fault (e.g., a shortcircuit) in an EV battery is detected. In some embodiments, one or moreof the switches may include logic to automatically open and close theircontacts in the event a fault is detected and communicate theoperational states to a central controller. In some embodiments,connection device 10 may be entirely or partially located in a circuitbreaker box or panel or in any of the inverters. For example, terminal15 may be connected to a circuit breaker panel to which the home backuploads are connected.

FIG. 2 illustrates a block diagram of an exemplary solar energygeneration and storage system 200 with multiple battery packs andelectric vehicle charging capability, according to some embodiments ofthe present disclosure. System 200 is similar to system 100 except thatthe backup energy capacity is increased to match or to be proportionalto the capacity of EV battery 144. FIG. 2 shows three (3) battery packsprovided for added capacity, however fewer or more battery packs may beused depending on the battery capacity of EV 140 and other factors. Forexample, each of the three battery packs may have an energy capacity of10 kWh, and battery 144 of EV 140 may have a capacity of 30 kWh, so thatthe three battery packs (battery packs 1 through 3) together match thebattery capacity of EV 140.

Other options may be to increase the power by using a larger sizestorage inverter, and/or a larger size PV inverter, or use multiplestorage inverters and multiple PV inverters. Higher energy capacity andhigher power capacity may be particularly useful in residential andcommercial (car ports) applications for fast charging or chargingmultiple EVs. In some embodiments, the power output rating of storageinverter 118 can be greater than that of PV inverter 106. For example,PV inverter 106 may have a rated power output equal to or less than 6kW, and storage inverter 118 may have a rated power output equal to orless than 12 kW or 18 kW, so that storage inverter 118 can supplyadditional power from more battery packs for fast charging the EV.

FIG. 3 illustrates a block diagram of an exemplary AC coupled solarenergy generation and storage system 300 with an AC batteryconfiguration and EV charging capability, according to yet otherembodiments of the present disclosure. In the embodiment shown, thebattery pack is integrated with the storage inverter in the same chassisas a storage unit 318. This configuration is generally denoted as an “ACbattery.” AC battery 318 may include battery module 324, DC/DCbuck/boost stage 320, bidirectional DC/AC (DC-AC) inverter 322, andbattery management system (BMS) 325. Depending on the voltage level ofthe battery module, DC/DC buck/boost stage 320 may or may not berequired. Battery module 324 may be a standard voltage battery pack(e.g., 48 V) or high voltage battery pack (e.g., 100 V or above). Whenbattery module 324 is a high voltage pack, DC/DC buck/boost stage 320may be omitted. Examples of high voltage battery packs have beendescribed in U.S. application Ser. No. 14/931,648, filed Nov. 3, 2015,entitled “High Efficiency High Voltage Battery Pack for Onsite PowerGeneration Systems,” the content of which is incorporated herein byreference in its entirety.

In some embodiments, when PV string(s) 104 do not generate energy and/orAC grid 114 is not available, AC battery 318 may supply energy to homebackup loads 116 using the energy stored in battery modules 324. Inother embodiments, battery 144 of EV 140 may be used to power homebackup loads 116 via the bidirectional car port link 340 and AC car-port123 through DC/AC (DC-AC) inverter 322. DC-AC inverter 322 is abidirectional inverter. In yet other embodiments, PV inverter 106 mayalso include an AC car port 123′ and operate in both grid-tied andoff-grid (grid outage) situations, where the charging power entirelydepends from the amount of solar energy available.

FIG. 4 illustrates a block diagram of an exemplary solar energygeneration and storage system 400 with electric vehicle chargingcapability according to still other embodiments of the presentdisclosure. System 400 differs from systems 100 and 200 in that thestorage inverter is not required. System 400 also differs from system300 in that DC/AC (DC-AC) inverter 322 in the AC battery is notrequired. In system 400, photovoltaic (PV) string(s) (or PV array) 404is one of the inputs to hybrid inverter power control system (PCS) 406.PV string(s) (PV array) 404 may include multiple PV panels connectedserially with an additive direct current (DC) voltage in the rangebetween 100 volts and 1000 volts depending on the number of panels,their efficiency, their output rating, ambient temperature and solarirradiation on each panel. In some embodiments, when the high voltage DCline from each PV string is input to hybrid inverter PCS 406, it issubjected to maximum power-point tracking (MPPT) at the string level.Alternatively, a number of modules in a respective string may include aDC optimizer that performs MPPT at the module level, rather at thestring level.

Hybrid inverter PCS 406 may include a DC/DC buck and/or boost converter409 at the inverter PV input side. DC/DC converter 409 is configured toensure that the voltage supplied to DC/AC inverter 411 is sufficientlyhigh for inversion. Hybrid inverter PCS 406 also includes a central DCbus (capacitor bank) 441 attached to a battery pack 418 so that the DCpower coming from PV string(s) 404 can be used to deliver DC power tobattery pack 418 to charge battery modules 424. This arrangement of thebattery pack is called a DC-coupled system because the interface betweenhybrid inverter PCS 406 and battery pack 418 is a DC bus 441. Batterypack 418 has a minimum and maximum associated operating voltage range.Because battery pack 418 has a maximum exposed input voltage limit that,in many cases, is lower than the theoretical maximum DC voltage comingoff of the PV string(s). Some embodiments include a DC/DC buck-booststage 420 between the central capacitor bank 112 and high voltagebattery pack 418. The inclusion of DC/DC buck-boost stage 420 willprevent voltages above a safe threshold from being exposed to highvoltage battery pack 418, thereby eliminating the possibility of damageto high voltage battery pack 418 from overvoltage stress. Alternatively,the function of DC/DC buck-boost stage 420 may be located in highvoltage battery pack 418. The inclusion of an asterisk denotes that theDC/DC buck-boost stage can be located either in the hybrid inverter PCS(shown by block 420) or in the high voltage battery pack (shown by block426) or in both systems. In some embodiments, if the DC/DC converter 409also includes a buck stage in addition to the boost stage then the DC/DCbuck-boost stage 420 may not be necessary. In some embodiments, whenthere are PV optimizers under modules for DC/DC conversion, then theremay not be a need for DC/DC converter 409 and/or 420. Battery pack 418includes battery modules 424 that may include low voltage batterymodules (e.g., 48 V) or high voltage battery modules (e.g., greater than100 V). In the case that battery modules 424 have low voltage batterymodules, DC/DC buck-boost converter 426 may boost the voltage to ahigher voltage level for charging high voltage battery 144 of EV 140.

When PV string(s) 404 generate energy, that energy can be supplied: (1)to charge high voltage battery pack 418 through DC/DC buck-boost stage420 (or 426) via DC car port 423, or (2) to charge battery 144 in EV 140through DC/AC inverter 411 and AC car port 453, or (3) to power homebackup loads 116 through DC/AC inverter 411, or (4) to AC grid 114through DC/AC inverter 411. When PV string(s) 404 do not generate energyand/or AC grid is not available, energy can be provided by battery pack418: (1) to power home backup loads 116 through DC/DC buck-boost 420 (or426) and DC/AC converter 411, or (2) to charge EV battery 144 in EV 140through the central DC bus 441 and DC car port 423 or (3) to AC grid 114through DC/DC Buck-Boost 426 (or 420) and DC/AC inverter 411. When PVstring(s) (PV array) 404 do not generate energy and AC grid is notavailable, EV battery 144 may be used to power back-up loads 116 via ACcar port 453 or via DC car port 423 through hybrid inverter PCS 406.Thus, system 400 has a bidirectional AC car port connection 471 denoted“Bidirectional car port (AC port)” in FIG. 4 and bidirectional DC carport connection 457 denoted “Bidirectional car port (DC port)” in FIG.4. Hybrid inverter PCS 406 controls the power flow to the back-up loadsvia internal anti-islanding and transfer relays during on-grid andoff-grid situations.

Referring to FIG. 4, EV 140 may have an internal AC/DC converter 142 forpower conversion in case of AC port 453 supplying power to EV battery144 through AC car port connection 471. AC/DC converter 142 may bebypassed when DC car port 423 supplies DC power directly to EV battery144 through DC car port connection 457. DC port 423 is particularlyadvantageous in that it can provide higher power (combination of PVstring(s) and high voltage battery pack), and high voltage directcharging improves charging efficiency, similar to superchargerscurrently available in the market.

In some embodiments, system 400 may include a site controller 430configured to automatically select among one or more of the PVstring(s), the battery pack, the EV battery, and the AC grid to providepower to the home backup loads. Site controller 430 may further beconfigured by a user to set the EV battery charging priority, i.e.,whether to supply power from the PV string(s) only, from the batterypack only, or from both, and in which order. In instances where theenergy from the PV string(s) and the battery pack is not sufficient, ormore energy/power is required, additional energy may be drawn from ACgrid 114 to charge EV 140.

In some exemplary embodiments, system 400 may receive commands from thesite controller to charge the battery pack using energy generated by thePV string(s) through the DC/DC buck-boost stage and DC bus 441. In someexemplary embodiments, system 400 may receive commands from the sitecontroller to charge the EV battery using energy generated by the PVstring(s) or energy stored in the battery pack through the DC/ACinverter, AC car port 453, and bidirectional AC car port 471. In someexemplary embodiments, system 400 may receive commands from the sitecontroller to charge the EV battery using energy stored in the batterypack through the DC car port 423 and the bidirectional DC car port 457.In some exemplary embodiments, system 400 may receive commands from thesite controller to power home backup loads through DC/AC inverters 411and interface 469 and/or provide surplus power to the AC grid throughDC/AC inverters 411 and interface 465.

In some exemplary embodiments, when the PV string(s) do not generateenergy and/or the AC grid is not available, site controller 430 mayinstruct system 400 to provide energy stored in the battery pack to thebackup loads through the DC/DC buck-boost 420 (or 426) and DC/ACinverter 411 and interface 469. In some exemplary embodiments, when thePV string(s) do not generate energy, the AC grid is not available, andthe battery pack is either not available or depleted, the battery 144 ofEV 140 can provide energy to the home backup loads through thedirectional AC/DC inverter 142 and bidirectional car port 471. EV 140can also provide energy to the AC grid through bidirectional car port471, AC car port 453, the connection 462 and DC/AC inverter 411. In someexemplary embodiments, when the PV string(s) do not generate energy andthe battery pack is not available, battery 144 of EV 140 can be chargedby the AC grid through connection 465, AC car port 453, andbidirectional car port 471.

In some embodiments, a connection device similar to connection device 10shown in FIG. 1A and described above may be used to connect DC/ACinverter 411 to the EV, the AC grid, and the home backup loads.

For slow charging, the total charging power can be limited to theinverter power rating or the combination of both the PV string(s) andthe battery pack in case of the DC car port. For example, the PVstring(s) may generate equal to or less than 6 kW and the battery packmay generate equal to or less than 6 kW, so that the charging power isequal to or less than 6 kW when one of PV string(s) and battery pack isused, or equal to or less than 12 kW when combined.

In some cases, when the power from the PV string(s) and/or from thebattery pack are not sufficient, or more power is required, then sitecontroller 430 may direct system 400 to receive power from the AC grid.In some embodiments, site controller 430 may be a central controllerthat connects to the hybrid inverter PCS to control the power flow ofthe hybrid inverter PCS and the battery pack. In some other embodiments,site controller 430 may include multiple microcontrollers distributed inDC/DC buck-boost stage 409, in DC/AC inverter 411, in DC/DC buck-booststage 420, and in battery pack 418, each of the microcontrollersmonitors and controls the performance of the system(s) they reside in.The microcontrollers may communicate with each other through acontroller bus, e.g., a controller area network (CAN) bus and the like.

FIG. 5 illustrates a block diagram of an exemplary solar energygeneration and storage system 500 with EV charging capability, accordingto other embodiments of the present disclosure. System 500 is similar tosystem 400 except that the backup energy capacity isincreased/multiplied to match or be proportional to the capacity of EVbattery 144. FIG. 5 shows three battery packs connected in parallelthrough a central DC bus to provide greater energy capacity, howeverfewer or more battery packs may be used depending on the battery size ofEV 140 and other factors.

The power supplied by energy generation and storage system 500 can beincreased in a number of ways. For example, a bigger DC/AC inverterstage may be used, a bigger DC/DC buck-boost stage may be used, and/ormultiple parallel-connected hybrid inverters may be used, or anycombination thereof. In some cases, large capacity and high power hybridinverters having multiple car ports (AC ports or DC ports or both) areessential in residential and commercial applications for simultaneouslycharging multiple EVs. In some embodiments, when the AC or DC car porton storage inverter 1 is being utilized, once the energy in system 1 isdepleted, then the energy from storage inverter 2 through X can beretrieved through the storage inverter 1 car port, as all of the thesesystems are electrically interconnected and can operate in conjunction.

In some embodiments, the PV string(s) may include a multitude ofstrings, each string may include a plurality of PV panels connected inseries to produce relatively high DC voltage, e.g., in the range between100 V to 1000 V. Each PV panel or PV string may include an optimizerconfigured to produce a fixed DC voltage to directly charge the highvoltage battery pack or charge the EV battery. In other embodiments,micro-inverters may be used instead of PV inverters.

FIG. 6 illustrates a block diagram of an exemplary AC coupled solarenergy generation and storage system 600 with electric vehicle chargingcapability including a PV inverter and multiple storage inverters,according to some embodiments of the present disclosure. System 600includes PV inverter 606 having DC/DC boost converter 609 that convertsthe voltage received from PV string(s) 104 to a higher voltage level,DC/AC inverter 611 coupled to DC/DC converter 609 through capacitor bank112. System 600 also includes a number of storage inverters 618-1 to618-X. The letter “X” at the end of “618-X” represents an integernumber. In some embodiments, PV inverter 606 and storage inverters 618-1to 618-X may be similar to the above-described PV inverter 106 andstorage inverter 118 shown in FIG. 1. System 600 has some advantagesover systems 100 and 200 as it has more storage capacity (more chargecapacity than system 100) and can provide more power (more power outputthan system 200).

PV inverter 606 provides energy to home backup loads 116 and AC grid 114through connection 641. PV inverter 606 also provides energy to battery144 of EV 140 through car port 123 and bidirectional AC port 642. WhenPV string(s) 104 does not generate energy, storage inverters 618-1,618-X may take over using the respective battery pack 102-1, 102-X. SiteController 630 is configured to control the energy flow eitherautomatically or per user's commands. It is noted that, although onebattery pack 1 and one battery pack X are shown, it is, however,understood, that battery pack 1 and/or battery pack X can have multiplebattery packs. System 600 also includes communication line 651connecting the storage inverters. Communication link 651 can be a wiredconnection line or a wireless communication link that enables thecommunication between the storage inverters. If there is low energy inany battery connected to the storage inverter, the other storageinverters can be used. For example, storage inverter 618-1 can take theenergy/power from storage inverter 618-X via the AC bidirectional port643. In some embodiments, storage inverter 618-X may have a car port123X that is similar to car port 123 and may also be connected to the ACgrid through storage inverter 618-X or with an external bypassmechanism.

FIG. 7 illustrates a block diagram of an exemplary DC coupled solarenergy generation and storage system 700 with electric vehicle chargingcapability including multiple hybrid inverters and battery packs,according to still other embodiments of the present disclosure. System700 includes a number of hybrid inverter power control systems (PCSs)connected in parallel. In some embodiments, each of the hybrid inverterPCS may be similar or the same as hybrid inverter PCS 406 of FIG. 4described above. System 700 has a number of advantages over system 400as it can provide more output power (more output power than system 400)because it has a number of hybrid inverter PCSs connected in parallel,and each of the hybrid inverter PCSs has it own battery pack, so thatsystem 700 also has a higher storage capacity that that of system 400.In the example shown in FIG. 7, two hybrid inverter PCSs 706-1 and 706-Xare shown, but it is understood that the number is arbitrarily chosenfor describing the example embodiment and should not be limiting.Accordingly, the reference number X can be any integer number N. Each ofhybrid PCSs 706-1, 706-X is connected to a corresponding battery pack718-1, 718-X (collectively referred to as battery pack 718). Batterypack 718 includes battery module 424 that may be a standard voltagebattery pack (e.g., 12V/48V) or high voltage battery pack (e.g.,100V/400V). When battery module 424 is a high voltage pack, DC/DCbuck/boost stage 420 may be omitted. An example of a high voltagebattery pack has been described in U.S. application Ser. No. 14/931,648,filed Nov. 3, 2015, entitled “High Efficiency High Voltage Battery Packfor Onsite Power Generation Systems,” the content of which isincorporated herein by reference in its entirety.

PV array 404 of FIG. 4 may include a plurality of separate PV strings.Each of the hybrid PCSs is connected to a corresponding PV string(s)(e.g., 404-1, 404-X, collectively referred to as PV string(s) 404hereinafter). In some embodiments, when PV string(s) 404 generateenergy, that energy can be supplied: (1) to charge battery pack 718through DC/DC buck-boost stage 420 (or 426), or (2) to charge battery144 in EV 140 through DC/AC inverter 411 and AC car port 453, or (3) topower home backup loads 116 through DC/AC inverter 411, or (4) to ACgrid 114 through DC/AC inverter 411. When PV string(s) 404 do not orpartially generate energy and/or AC grid 114 is not available, energycan be provided by battery pack 718: (1) to power home backup loads 116through DC/DC buck-boost 420 (or 426) and DC/AC converter 411, or (2) tocharge EV battery 144 in EV 140 through the central DC bus and DC carport 423 or (3) to AC grid 114 through DC/DC buck-boost 426 (or 420) andDC/AC inverter 411. When PV string(s) 404 do not generate energy and ACgrid 114 is not available, EV battery 144 may be used to power homeback-up loads 116 via AC car port 453 or via DC car port 423 throughhybrid inverter PCS 706-1. Thus, system 700 has a bidirectional AC carport 453 denoted “Bidirectional car port (AC port)” in FIG. 7 and abidirectional DC car port 423 denoted “Bidirectional car port (DC port)”in FIG. 7. The hybrid inverter PCSs can be communicated with each otherthrough a communication link 751. Communication link 751 can be a wiredconnection line or a wireless communication link that enables thecommunication between the hybrid inverter PCSs. For example, hybridinverter PCS 706-1 can take the energy/power from hybrid inverter PCS706-X via an AC bidirectional port 743. In some embodiments, hybridinverter PCS 706-X may have car port 453X that is similar to car port453 and may also be connected to the AC grid. In some embodiments, whenthe AC or DC car port on hybrid inverter PCS 1 is being utilized, oncethe energy in system 1 is depleted, then the energy from hybrid inverterPCS 2 through X can be retrieved through the hybrid inverter PCS 1 carport, as all of the these systems are electrically interconnected andcan operate in conjunction.

In some embodiments, system 700 may include a site controller 730configured to automatically select among one or more of the PVstring(s), the hybrid inverter PCSs, the EV battery, and the AC grid toprovide power to the home backup loads. Site controller 730 may furtherbe configured by a user to set the EV battery charging priority, i.e.,whether to supply power from the PV string(s) only, from the batterypack only, or from both, and in which order. In instance where theenergy from each of the PV string(s) and the battery pack is notsufficient, or more energy is required, energy can be drawn from all ofthe hybrid inverter PCSs of the system, or additional energy may also bedrawn from AC grid 114 to charge EV 140. In some embodiments, whenbattery pack 718 does not have enough energy, battery 144 of EV 140 maybe used to supply energy to home backup loads 116 through ACbidirectional car port 744 and DC/AC inverter 411.

FIG. 8 illustrates a block diagram of an exemplary solar energygeneration and storage system 800 with electric vehicle chargingcapability including an AC coupled solar energy generation and storagesystem of FIG. 1 and one or more hybrid inverters and battery packs,according to still other embodiments of the present disclosure. System800 allows users to add capacity and output power as needed. Forexample, a user can add one or more storage inverters to an alreadyavailable PV inverter to meet the need of capacity increase. Asadditional capacity and output power are further required, the user mayadd one or more hybrid inverter PCSs to the already installed PVinverter and storage inverter based on advances in inverter technology.

Referring to FIG. 8, system 800 may include a PV inverter 806 AC-coupledto a storage inverter 818. PV inverter 806 and storage inverter 818 maybe one of the AC-coupled systems of FIGS. 1, 2, and 3 described in abovesections. System 800 also includes a hybrid inverter PCS 809 including abattery pack 818. Battery pack 818 includes a battery module 824 thatmay include a number of standard (low voltage) batteries (e.g., 12V to48V) or high-voltage batteries (>100V). Hybrid inverter 809 togetherwith battery pack 818 may be one of the DC-coupled system of FIGS. 4, 5,and 7 described in above sections. The AC coupled system and the DCcoupled system can be are connected together through an AC bidirectionalconnection port 843 to provide a higher power to home backup loads 116and/or AC grid 114. Although one hybrid inverter PCS is shown in system800, it is, however, understood that system 800 can have any number ofhybrid inverter PCSs. It is also understood that, although only onebattery pack 1 and one battery pack X are shown, system 800 may have anynumber of battery packs 1 and any number of battery packs X. Althoughnot shown in FIG. 8, it will be appreciated that PV inverter 806 mayinclude a bidirectional DC car port 156″ and bidirectional DC connection157″ for supplying DC power to EV 140 when PV string 104 generatessufficient electrical energy and for receiving DC power from EV 140 whenPV string does not provide adequate electrical energy.

System 800 also includes a communication link 851 connecting storageinverter 818 (the AC coupled system) and hybrid inverter PCS 809 (DCcoupled system). Communication link 851 can be a wired connection lineor a wireless communication link that enables the communication betweenstorage inverter 818 and hybrid inverter PCS 809. For example, storageinverter 818 can take the energy/power from hybrid inverter PCS 809 viaan AC bidirectional port 843, or vice versa. In some embodiments, hybridinverter PCS 809 may have a car port 823 for DC charging battery 144 ofEV 140. In some embodiments, car port 123 can be in each inverter.

In some embodiments, system 800 may also include a site controller 830configured to automatically select among the PV string(s), the PVinverter, the storage inverter, the hybrid inverter PCS, the EV battery,and the AC grid to provide power to the home backup loads. Sitecontroller 830 may further be configured by a user to set the EV batterycharging priority, i.e., whether to supply power from the PV string(s)only, from the battery pack(s) (e.g., 102, 818) only, or from both, andin which order.

FIG. 9 illustrates a block diagram of an exemplary solar energygeneration and storage system 900 with electric vehicle chargingcapability including a PV inverter and one or more hybrid inverters andbattery packs, according to still other embodiments of the presentdisclosure. System 900 differs from system 800, in that the storageinverter is omitted. System 900 has a number of advantages. For example,a PV inverter 906 is first installed to provide energy to home backuploads 116 or AC grid 114. As such, any excess energy that is notconsumed by backup loads 116 will be wasted or fed to the AC grid. Ahybrid inverter PCS 909 including a battery pack 918 may be economicallyadded to efficiently store the excess energy and also to add power tothe system. PV inverter 906 can be above-described PV inverter 106 inFIG. 106. Hybrid inverter PCS 909 and battery pack 918 may be similar tohybrid inverter PCS 809 and battery pack 818 that have been described inthe sections above. It is noted that the battery pack may include anumber of low voltage or high voltage batteries as described in sectionsabove, so that the description will not be repeated for the sake ofbrevity.

FIG. 10 illustrates a block diagram of an exemplary solar energygeneration and storage system 1000 with electric vehicle chargingcapability including a single stage PV inverter and a storage inverter,according to still other embodiments of the present disclosure. System1000 is similar to system 100 with the difference that PV inverter 1006does not include a DC/DC boost converter because the PV string(s) 1004is a long PV string with high voltage output (e.g., 400V to 1000V). Thisis the case when a large number of solar PV modules can be installed,e.g., in farmland or in areas with a large surface. In some embodiments,PV inverter 1006 may be a single stage DC/AC inverter when the voltageprovided by long PV string(s) 1004 is sufficiently high.

FIG. 11 illustrates a block diagram of an exemplary solar energygeneration and storage system 1100 with electric vehicle chargingcapability including a single stage PV inverter 1106 with a PV optimizer1104 and a storage inverter 1118, according to still other embodimentsof the present disclosure. System 1100 is similar to system 1000 withthe difference that system 1100 includes a number of PV optimizerstrings (e.g., string 1, string 2) instead of the long string(s) insystem 1000. Each string may include a number of PV optimizers that areinterconnected with each other. Although two strings of PV optimizersare shown in the example embodiment in FIG. 11, it is understood thatsystem 1100 can have any number N of PV optimizer strings. In someembodiments, the PV optimizers strings are located on the roof. In otherembodiments, the PV optimizers strings are located below the roof Insome embodiments, the PV optimizers may include buck and/or boostconverters that can be connected in series or in parallel dependent fromapplications. DC/AC inverter 1111 is coupled to the PV optimizersthrough capacitor bank 112 and converts the received DC energy into ACenergy to provide to home backup loads 116 or to storage inverter 1118.System 1100 may include a site controller 1130 configured toautomatically select between PV inverter 1106 and storage inverter 1118to provide power to the home backup loads or to the AC grid.

FIG. 12 illustrates a block diagram of an exemplary solar energygeneration and storage system 1200 with electric vehicle chargingcapability including a plurality of micro-inverters 1204 and a storageinverter 1218, according to still other embodiments of the presentdisclosure. System 1200 is similar to system 1100 with the differencethat system 1200 includes a number of micro-inverters connected inseries and in parallel to directly provide AC power to home backup loads116 without a PV inverter of system 1100. System 1200 may also include asite controller 1130 configured to automatically select betweenmicro-inverters 1204 and storage inverter 1218 to provide power to thehome backup loads, to the AC grid, or to battery 144 of EV 140. In someembodiments, the systems 1000, 1100 and 1200 may have hybrid inverterPCSs instead of storage inverters.

Embodiments of the present disclosure may be implemented in off-gridbattery charging stations set up along roads or highway exits. Suchcharging stations may include a roof covered with photovoltaicstring(s), and all other components shown in the various embodimentsdisclosed herein. The solar energy generation and storage system,including, e.g., PV inverter(s) and/or storage inverter(s) and/or hybridinverter(s) and low voltage/high voltage battery packs, may be housed ina secure room that is only accessible to authorized personnel, e.g., amaintenance operator. The solar energy generation and storage system maybe a stand-alone system that is not connected to the AC grid. A sitecontroller similar to those shown in FIG. 1-12 may enable a user toselect between a slow charging (AC charging) mode or fast charging (DCcharging, supercharging) mode. Such system may also include an automaticpayment system that can bill the user according to the amount of energyused or the selected charging mode.

The embodiments described herein are not to be limited in scope by thespecific embodiments described above. Indeed, various modifications ofthe embodiments, in addition to those described herein, will be apparentto those of ordinary skill in the art from the foregoing description andaccompanying drawings. Further, although some of the embodiments havebeen described herein in the context of a particular implementation in aparticular environment for a particular purpose, those of ordinary skillin the art will recognize that their usefulness is not limited theretoand that they can be beneficially implemented in any number ofenvironments for any number of purposes. Accordingly, the disclosureshould be construed in view of the full breath and spirit of theembodiments as disclosed herein.

What is claimed is:
 1. An inverter comprising: a battery pack connection for supplying energy to or receiving energy from a battery pack; an AC grid connection for supplying power to or receiving power from an AC grid; a connection for supplying power to a home back-up load; an electric vehicle connection for supplying to and receiving power from an electric vehicle (EV) battery; and a control input configured to receive one or more control signals for controlling the flow of power within the inverter, wherein the inverter, under the control of the one or more control signals, inverts power received from the battery pack and provides the inverted power to the electrical vehicle connection to charge the EV battery.
 2. The inverter of claim 1 wherein the inverter is a storage inverter that further comprises a DC/DC buck-boost stage configured to couple to the battery pack, and a DC/AC inverter configured to selectively couple to a PV inverter, to the AC grid and to the home back-up load.
 3. The inverter of claim 2 wherein the storage inverter comprises a DC car port coupled to the DC/DC buck-boost stage and configured to supply DC power to and receive DC power from the EV battery.
 4. The inverter of claim 1 wherein the inverter is a hybrid inverter that further comprises a first DC/DC buck-boost stage configured to couple to one or more PV strings, and a DC/AC inverter configured to selectively couple to the AC grid, to the home back-up load, and to the EV battery under the control of the one or more control signals.
 5. The inverter of claim 4 wherein the hybrid inverter further comprises a second DC/DC buck-boost stage coupled between the first DC/DC buck-boost stage and the battery pack and configured to supply power to the battery pack or receive power from the battery pack.
 6. The inverter of claim 5 wherein the hybrid inverter further comprises a DC car port connection coupled to the second DC/DC buck-boost stage and configured to supply DC power to or receive DC power from the EV battery.
 7. A system for energy conversion with electric vehicle charging capability, the system comprising: a photovoltaic (PV) inverter configured to receive DC power provided by a photovoltaic (PV) array and to generate AC power; a storage inverter coupled to the PV inverter, the storage inverter comprising: a battery pack connection for supplying energy to or receiving energy from a battery pack; an AC grid connection for supplying power to or receiving power from an AC grid; a connection for supplying power to a home back-up load; an electric vehicle connection for supplying power to or receiving power from an electric vehicle (EV) battery; and a controller for generating one or more control signal to control the flow of power through both the PV inverter and the storage inverter, wherein the system, under the control of the one or more control signals, converts power received from one of the PV string and the battery pack to AC power and provides the converted power to the electric vehicle connection to charge the EV battery.
 8. The system of claim 7, wherein the storage inverter further comprises: a buck-boost stage coupled to the battery pack; a bidirectional DC-AC inverter coupled to the PV inverter and configured to: convert the AC power received from the PV inverter to DC output power to charge the battery pack through the buck-boost stage, or convert DC power received from the battery pack to AC power and selectively provide the AC power to the home back-up load and the AC grid; and a DC link coupled between the buck-boost stage and the bidirectional DC-AC inverter.
 9. The system of claim 8, wherein the storage inverter further comprises a DC connection coupled to the buck-boost stage and configured to directly DC charge the EV battery.
 10. The system of claim 9, wherein the DC connection is coupled to the DC link.
 11. The system of claim 7, wherein the bidirectional DC-AC inverter is coupled to the EV battery through the electric vehicle connection.
 12. The system of claim 7, wherein the battery pack is integrated in the storage inverter.
 13. The system of claim 7, wherein the storage inverter further comprises a plurality of switches configured to set the system into a plurality of operation modes under the one or more control signals provided by the controller.
 14. A system for energy conversion with electric vehicle charging capability, the system comprising: a hybrid inverter comprising: a first DC/DC converter stage configured to receive power from a photovoltaic (PV) array; a capacitor bank coupled to the first DC/DC converter stage and configured to store DC energy; a DC-AC inverter coupled to the capacitor bank: a battery pack connection for supplying energy to or receiving energy from a battery pack; an AC grid connection for supplying power to or receiving power from an AC grid; a connection for supplying power to a home back-up load; and an electric vehicle connection for supplying power to or receiving power from an electric vehicle (EV) battery; and a controller for generating one or more control signals to control the flow of power within the hybrid inverter, wherein the hybrid inverter, under the control of the one or more control signals, converts power received from at least one of the PV array and the battery pack and provides the converted power to charge the EV battery via the electric vehicle connection.
 15. The system of claim 14, further comprising: a second DC/DC converter stage coupled between the capacitor bank and the battery pack and configured to buck or boost the stored DC output voltage to a suitable voltage for charging the battery pack, or to buck or boost a battery pack voltage to a suitable voltage for supplying to the DC-to-AC inverter.
 16. The system of claim 15, wherein the second DC/DC converter stage is integrated in the inverter.
 17. The system of claim 15, wherein the second DC/DC converter stage is integrated in the battery pack.
 18. The system of claim 15, wherein the hybrid inverter further comprises a DC car connection coupled to the second DC/DC converter stage and configured to supply DC power for charging the EV battery.
 19. The system of claim 15, wherein the battery pack comprises a plurality of unit battery packs coupled in parallel and to the inverter through the battery pack connection for supplying stored energy to or receiving energy from the PV array, the AC grid, or the EV battery.
 20. The system of claim 15, further comprising a PV connection configured to connect to the PV array including a plurality of separate PV strings, and a plurality of hybrid inverters, each of the hybrid inverters comprising a unit DC/DC converter stage coupled to one of the PV strings and a DC-AC inverter, wherein the DC-AC inverters are coupled in parallel to supply added AC power to the AC grid, the home backup load, or the EV battery. 